Cutting-knife for calenders.



G. H. LEWIS,

CUTTING KNIFE FOR CALENDERS.

APPLICATlON FILED MAY 21. 1915.

1,151,527, Patented Aug. 24, 1915.

2 SSSSSSSSSS ET I.

WITNESSES:

A TTOR NE Y3 G. H. LEWIS.

CUTTING KNIFE FOR'CALENDERS.

APPLICATION FILED MAY 21. 1915.

Patented Aug. 24, 1915.

2 SHEETS-SHEET 2.

WITNESSES:

IN V EN TOR.

By k f.

A TTORNE YS GEORGE E. LEWIS, OF CHICOPEE FALLS, MASSACHUSETTS, ASSIGNOR TO THE FISK Specification of Letters Patent.

CHICOPEE FALLS, MASSACHUSETTS, A CORPORATION OF CUTTING-KNIFE FOR CALENDERS.

ratenteaaag. 2a, 1915.

Application filed may 21, 1915. Serial No. 29,666.

To all whom. it may concern:

Be it known that I, GEORGE H. Lnwrs, a citizen of the United States of America, residing in the city of Chicopee Falls, county of Hampden, and State of Massachusetts, have invented certain new and useful Improvements in Cutting-Knives for Calenders, of which the following is a specification.

lhis invention relates to cutting knives for-calenders, which are arranged to slit by the roll; With-such an arrangement the.

cutting is accomplished by thetop .of the knife rather than bythe pointand the dragging action of the material being calendered tends to force the knife away from the roll. To insure proper cutting action with the arrangement just described, it has been found necessary to use strong elastic means to force the knife against the roll and the use of said means has been found in ractice to score the periphery of the calen er roll in a short time. Furthermore, the use of the elastic means prevents quick withdrawal of the knife from the roll since said means must first be disconnected. These disadvantages I seek to overcome by my invention.

An object of this invention is to provide a knife or plurality of knives for slitting material during the calendering operation,

which are pivotally mounted and arranged to engage the calender roll by gravitational action and to be quickly and conveniently withdrawn from cutting position.

Another object is to provide a device of the class described, wherein the knives are so arranged that the pressure thereof against the material being calendered is increased by the drag of material itself.

A further object is to provide improved means for axially positioning a set of knives 'on a pivotal support, which permits instant tional view partly in section of a single cutting. knife; and Fig. 4 is a sectional view taken on the line .l4= of Fig. 3 and looking in the direction of the arrows.

Referringto the drawings in detail; it represents a calender roll of the usual type which is rotatably mounted in a frame A and driven in any suitable manner. The roll 0, shown in the drawings may be arranged for steam and hot water heating in the usual manner, if desired, and preferably should be, when used for calendering rubber stock. A rod Z) is mounted in parallel and spaced relation with the roll a and is suitably fixed in brackets secured to the frame A. The rod 6 has a key 0 fixed therein which extends entirely across the rod. The latter serves to support a plurality of knife supporting arms in a manner to be described.

Referring more particularly to Figs. 3 and 4: 1 represents a sleeve having an integral flange 2, which is slidable on the rod 6 but is held against rotation by the key 0. The sleeve 1 is cutaxially in several places as indicated at 4 in Figs. 3 and a and is threaded at one end to receive a nut 5. Suitable notches 3 and 6 are cut in the periphery of the flange 2 and nut 5 to receive a spanner wrench. By tightening the nut 5 the sleeve 2 is held to the shaft 12 by frictional resistance. In practice the amount of this frictional resistance is so gaged that the sleeve 1 will not be displaced from its axial position on the shaft 7) by ordinary vibrations but may be readily moved by the operator without loosening the nut 5.

Loosely mounted on the sleeve 1 and loosely held between the head 2 and nut 5,

are a pair of arms 8, which are freely and independently movable on the sleeve. Each of these arms supports a knife 9, which is sharpened to a cutting edge at 10. Each knife 9 is clamped to one face of an arm 8 by a plate 11, which is secured to the arm. by a pair of cap screws 12. By this arrangement the inclination of the knife 9 relative to the arm 8 may be' varied within limits as desired. In Figs. 3 and 4, the sleevel has been shown as supporting a pair of arms 8 and, while this arrangement is preferable in many cases, a single arm only may be mounted on the sleeve as shown at the left of Fig. 2.

N The operation of the cutting device de-' when a knife 9 is in cutting position, it so engages the periphery of theroll that the only force acting to hold theknife against the roll a is that due to gravity. In practice, however, and especially when rubber stock is cut, it has been found that the material (Z exerts dragging action on the lmife 9 to still further increase the pressure thereon. This increased pressure is in reality 'due to a toggle action wherein lines drawn from the center of the roll at and the center of rod 6 to the point of engagement of the knife 9 with the roll may be considered as links and. the force acting on the toggle as the moving material at; Obviously, as the two links of the toggle are moved downwardly to approach a single straight line drawn between the centers of roll a and rod 6 so that the three points of the toggle all lie in a same line, the pres: sure on the lmife 9 is greatly increased and as the links are moved upwardly the pressure is diminished. The range of pressure due to this toggle arrangement is, therefore, great and any pressure from a slight one to one great enough to break the knife may be obtained. Thus, in practice, a wide range '-.of adjustment is provided for the knives 9 to permit the slitting of various materials. In former structures, where the point of contact of the knife with the roll lay below the line connecting the pivotal points of the two elements, this dragging action was ob jectionable, as it diminished the pressure of the knife. It will be clearly obvious from the above analogy that the drag of the 'material tends tobreak the toggle and force the knife away from the material.

Thus, heavy springs were necessary to overcome the eifect of the drag and to supply the necessary pressure. The omission of the springs, heretofore used, and the improved arrangement wherein the dragging action is turned to advantage permits a very simpleyet highly efficient structure.

1. A cutting mechanism for slitting a web of material, comprising in combination, a roll for feeding the web and a knife supported in position to bear on said roll and to be forced against said web by the rotational action of the roll.

2. A cutting mechanism for slitting material during a calendering operation, comprising in combination, a roll and a pivotally supported knife arranged to engage and to be forced against said roll by gravitational action.

3. A cutting mechanism for slitting material during a calendering operation, comprising in combination, a roll and a pivotally supported knife arranged to be forced against said roll by gravitational action and the dragging action of the calendered material.

4. A cutting mechanism for slitting materialduring a calendering operation, comprising in combination, a roll over which the material is arranged to pass and a pivotally supported knife arranged to contact with the roll to slit the materialand to be forced thereagainst by gravitational action,

the point of contact of the knife with the roll being so located relatively to the center of the roll and said pivotal support that the pressure on the knife is increased by the drag of the material.

5. A cutting device for calenders, adapted to slit material as it is calendered, comprising in combination, a suitable calender roll, a rod adjacent said roll, a sleeve azu'ally adjustable thereon and a knife rotatably supported on said sleeve arranged to' engage said roll and to be forced against said roll by gravitational action, all constructed and arranged so that the pressure on said knife is accentuated by the dragging action of the calendered material.

6. A cutting device for calenders, adapted to slit material as it is calendered, comprising in combination a suitable calender roll, a rod mounted adjacent thereto, a plurality of sleeves axially adjustable on said rod, and one or more knives rotatably supported 011 each of said sleeves, each thereof arranged to engage the periphery of said roll and to be forced against said roll by gravitational action, all constructed and arranged so that the pressure on said knife is accentuated by the dragging action of the calendered material, each of said knives be- -10 ing freely and independently movable on their supporting sleeve and arranged to be readily removed from said roll at will.

GEORGE H. LEWIS. 

